Electric heating – Metal heating – By arc
Patent
1997-09-10
2000-05-02
Evans, Geoffrey S.
Electric heating
Metal heating
By arc
21912168, B23K 2618, B23K 2614
Patent
active
060575255
ABSTRACT:
A method and apparatus for micromachining and microdrilling which results in a machined part of superior surface quality is provided. The system uses a near diffraction limited, high repetition rate, short pulse length, visible wavelength laser. The laser is combined with a high speed precision tilting mirror and suitable beam shaping optics, thus allowing a large amount of energy to be accurately positioned and scanned on the workpiece. As a result of this system, complicated, high resolution machining patterns can be achieved. A cover plate may be temporarily attached to the workpiece. Then as the workpiece material is vaporized during the machining process, the vapors condense on the cover plate rather than the surface of the workpiece. In order to eliminate cutting rate variations as the cutting direction is varied, a randomly polarized laser beam is utilized. A rotating half-wave plate is used to achieve the random polarization. In order to correctly locate the focus at the desired location within the workpiece, the position of the focus is first determined by monitoring the speckle size while varying the distance between the workpiece and the focussing optics. When the speckle size reaches a maximum, the focus is located at the first surface of the workpiece. After the location of the focus has been determined, it is repositioned to the desired location within the workpiece, thus optimizing the quality of the machined area.
REFERENCES:
patent: 4105919 (1978-08-01), Bridges et al.
patent: 4286212 (1981-08-01), Staebler et al.
patent: 4530600 (1985-07-01), Lopez
patent: 4547651 (1985-10-01), Maruyama
patent: 4905252 (1990-02-01), Goldberg et al.
patent: 4917484 (1990-04-01), Heinz
patent: 5057664 (1991-10-01), Johnson et al.
patent: 5235263 (1993-08-01), Boston et al.
patent: 5289557 (1994-02-01), Sheinis et al.
patent: 5334816 (1994-08-01), Sugiyama
patent: 5359558 (1994-10-01), Chang et al.
patent: 5371570 (1994-12-01), Morris et al.
patent: 5434882 (1995-07-01), Chang
patent: 5493096 (1996-02-01), Koh
patent: 5562842 (1996-10-01), Laferriere
patent: 5744780 (1998-04-01), Chang et al.
R. Steven Hargrove, et al; "Laser Materials Processing Applications at Lawrence Livermore National Laboratory," SPIE, vol. 1859 Laser Isotope Separation (1993), pp. 263-272.
K.I. Zemskov, et al.; "Laser Machining of Objects with Simultaneous Visual Monitoring in a Copper Vapor Oscillator-Amplifier System," Sov. J. Quantum Electron, 14 (2), Feb. 1984, 0049-1748/020288-03, .COPYRGT.1984 American Institute of Physics, pp. 288-290.
Product Literature for "Optics for Research--Precision Optical Components", 2 pages. .COPYRGT.1988.
J.J. Chang, et al., "Precision Micro Drilling With Copper Vapor Lasers," ICALEO (1994), pp. 323-332.
Company Literature for Physik Instrumente (PI), 3 pages. (No Date).
W.M. Steen. "Laser Material Processing," Springer-Verlag (1991), pp. 85-87.
R. Jones, C. Wykes, "Holographic and Speckle Interferometry: A discussion of the theory, practice and application of the techniques," Cambridge University Press (1989), pp. 52-55.
Melles Griot Optics Guide V, "Retardation Plates ," pp. 14-28 to 14-29. (No Date).
J.J. Chang, "Copper-Laser Oscillator With Ajoint-Coupled Self-Filtering Injection," reprinted from Optics Letters, vol. 20, No. 6 (Mar. 15, 1995), pp. 575-577.
Chang Jim
Dragon Ernest P.
Warner Bruce E.
Beck, Esq. David G.
Evans Geoffrey S.
United States Enrichment Corporation
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